I'm now facing a big issue trying to make a serial UDF parallel.
This UDF is divided into 2 parts. An execute_on_demand at the begining to read and send to nodes some scheme variables and the second one that is used to simulate some reaction rates at wall.

The UDF works perfectly in serial but I need now to adapt it for parallel computation.
The main problem seems to be the fact that I have to call a face on a different thread.